i am looking at an 84 firebird with an lg4. it already has a holley carb, headers + catback, subframe connectors, and by the time i get it to the track it sould have full tubular suspension in the rear. my question is if i put in a mild performance cam, like this one(http://store.summitracing.com/partde...4&autoview=sku )
and maybe a dualplane performance intake(not sure which brand would be best)

should the motor really "wake up" due to the headers and frreeflowing exhaust already installed? i am new to carbs, but i no many people that can help with that. i know the lg4 has a lower compression around 8.5:1. is there a way to compensate for that with the cam, or timing?

what kind of et's could i expect with that set up?

 

I like the comp cams xtreme energy line, I ran the xe268 in basically the same setup as you but a 327 instead of a 305, you're exhaust is probably better than mine. 3"? the car ran consistent 14.5's.

I'd go with an xe262 or xe268, but without a converter it'll feel kinda gutless off the line, especially with the latter.

I thought the lg4 had 9:1 compression. There's no way to compensate for low compression.

 

I have the comp XE268 in my 305ho, best of a 13.9 not tuned at all and on street tires.

 

I'm running the setup below in my signature, which is close to what your talking about running. I've got the K1102 cam, you're looking at the K1104, which is just a bit more duration and lift. Just be sure converter and gears are on your list if you're planning on much cam with a 305. You might as well beef the valvetrain so you can rev through that cams full potential, I start falling off around 5300rpm, and I think its valve float. I'm gonna step up to some Comp 981 valve springs this winter to see if I better valvetrain control improves my topend.

Is the carb a VS, or a double pump? Just curious, if a double pump you'll wanna much sure again that you've got a decent converter.

I'm having excellent luck w/ my ZZ3 manifold, which is just a GM knockoff of an Edlebrock Performer manifold. I'm sure there are a few other options as well.

With what I've got now, I think I'm solidly at a mid 14, I can put a few cars on a 05 Grand Prix GTP (the supercharged verson) that runs 14.7's, and I've also been able to consistently beat a couple of Cobalt SS's which are mid 14 cars, so I feel safe saying I'm good for at least a 14.6, I should have actually numbers this fall.

 

Stock '86 LG4 & TH700, ZZ3 intake, GTA cat-back, open element air cleaner, 3.08 peg-leg - best 16.8 @ 80 mph at 5800' which translates to about 15.7 @ 85 mph at sea level.

Add ported heads, Crane 2050 cam, L69 dual snorkel air cleaner, Hooker 2055 headers and 3" the rest of the way back, 2300 stall converter, 2.93 posi - best 15.75 @ 90 mph at 5800', or 14.6 @ 97 mph sea level. This was probably held back because the tired TH700 wouldn't shift 2-3 at WOT.

With everything pretty much the same except ZZ4 cam in a 350 shortblock, ceramic coat the headers, freshened TH700 with same converter (it just stalls 200 RPM higher now), port match the intake, results in sig.